The right inframesocolic space is smaller than its left counterpart. It is bounded by the transverse colon anterosuperiorly, the mesentery of the ascending colon on the right, the root of the small bowel mesentery on the left and the apex lying inferiorly at the ileocecal junction. Upon examination of the floor of the right inframesocolic space, the lower pole of the right kidney can be felt on the right side. Just to the left of this, the descending part of the duodenum (D2) turns transversely into the transverse duodenum (D3).

It is important to note that fluid tracking down from the right inframesocolic space into the pelvis must pass forwards over the lower ileum. This is compared to the left inframesocolic space where there is free passage to the pelvis.

The left inframesocolic space is quadrilateral in shape and is the larger of the two compartments. It is in free communication with the pelvic peritoneal space on the right of the midline. The sigmoid colon and its associated mesentery form a partial barrier on the left of the midline. The upper border of the space is the attachment of the transverse mesocolon, the left border is the mesentery of the descending colon, the right border is the root of the small bowel mesentery.

The inframesocolic space also contains the right and left paracolic gutters which are peritoneal recesses on the posterior abdominal wall lateral to the ascending and descending colon respectively. The right paracolic gutter is continuous superiorly with the right subhepatic and right subphrenic spaces. It is larger than the left paracolic gutter, which is partially separated from the left subphrenic spaces by the phrenicocolic ligament. Both paracolic spaces are in continuity with the pelvic peritoneal spaces.